811: When sent on 1081, tv reads 520p

[JAL]

811: When sent on 1080i, tv reads 520p

I have a Sharp LCD TV. When I use component outputs with the 811 set on 1080i, the TV receives 1080i. When I switch to DVI, the tv reads 520p. When I switch the 811 to 720p, through the DVI the tv will read 720p. Is this the 811 or the tv? Thoughts?

 

[goaliebob99]

maybe your tv cant do 1080i....

 

[DRGingras]

It's your LCD doing this. When you're using component, the path is all analog. Your display is willing to keep it that way. When you're using DVI, the display wants to convert 1080i (interlaced) to a digital (progressive) path. 540p is close to being the digital equivilant to 1080i. However, when you send 720p to your display via DVI, the signal is already digital, so your display doesn't need to make any conversions.

Nothing wrong or bad happening here - just pick the combo that looks the best to you and enjoy!

Dave

 

[JAL]

Thanks, but why can't the tc display 1080i with the DVI connection?

 

[Stacy A]

DRGingras is partially right. Actually, your display's native scan rate is 720p. It cannot do 1080i, so when you send it a 1080i source, it converts it to 540p (which is half of 1080i). You get the full 720p when you send it a 720p source. Most, or all, LCD, plasma, and DLP HDTV's have a native scan rate of 720p. Most, if not all, CRT based HDTV's are 1080i, natively. You didn't mention it, but I wonder if if you could tell a significant difference between 720p and 540p on your display?

 

[JAL]

Yes. The 540p looks blurrier than 720p. The 1080i through the component blows both 540p and 720p away in my opinion. And, I guess i'm still a little confused about why the tv can display 1080i through component but not DVI. Thanks.

 

[Stacy A]

Yes. The 540p looks blurrier than 720p. The 1080i through the component blows both 540p and 720p away in my opinion. And, I guess i'm still a little confused about why the tv can display 1080i through component but not DVI. Thanks.

Your TV's native scan rate is 720p, and since the signal is kept digital all the way into your TV through the DVI cable, it can only use it as 720p. It will make no conversions. If I am not mistaken, using a DVI cable means any conversions (1080i-->720p) must be made before it goes into the DVI cable. Using component video cables means the signal has been converted to analog before it goes to your TV and your TV is free to convert that signal to 720p however it wants to. I'm pretty sure the quality difference you are seeing is a result of the quality of the scalers being used - the TV's or the receiver's. I'm probably wrong about it though.

My father-in-law has a Samsung DLP that is natively 720p. He prefers to use the component video out rather than the DVI and get this, he keeps his 811 set to output 1080i. It makes a much better picture. I don't really understand it myself, but I do know the Samsung uses a Faroudja de-interlacer, so I think when it gets 1080 lines and deinterlaces to 720p, it just produces a beautiful picture.

 

[douweb]

Your TV's native scan rate is 720p, and since the signal is kept digital all the way into your TV through the DVI cable, it can only use it as 720p. It will make no conversions. If I am not mistaken, using a DVI cable means any conversions (1080i-->720p) must be made before it goes into the DVI cable. Using component video cables means the signal has been converted to analog before it goes to your TV and your TV is free to convert that signal to 720p however it wants to. I'm pretty sure the quality difference you are seeing is a result of the quality of the scalers being used - the TV's or the receiver's. I'm probably wrong about it though.

My father-in-law has a Samsung DLP that is natively 720p. He prefers to use the component video out rather than the DVI and get this, he keeps his 811 set to output 1080i. It makes a much better picture. I don't really understand it myself, but I do know the Samsung uses a Faroudja de-interlacer, so I think when it gets 1080 lines and deinterlaces to 720p, it just produces a beautiful picture.

I have the exact same experience as your father-in-law (same equipment); though it can also be just my eyes like it that way.

Just like you I do not understand it totally either ... I know by theory it should not.

 

[sprintcarcrazy]

I Also have a Sharp 37in LCD, I have an issue with the 811's and DVI. It is very fuzzy/blurry using DVI, but very nice using component. It appears to be a compatability issue. I also have used a Samsung OTA HD using the DVI and it works fine. The TV shows 1080I using component or DVI but with the 811, it's fuzzy through the DVI. I have called Sharp but not got anywhere with it.

For now, I am using the compnent cable for the 811. I have another 811 on a 26in JVC LCD and use the DVI and it looks great.

I leave the 811 on Both sets at 1080I, a much better picture.

The Sharps Native Resolution is 720P and the JVC is 1080I

I get a better picture using the component and 1080I through the 811 than 720P and DVI cable. Although I loose the fuzzyness at 720P, the picture is not as detailed.

The Samsung box set at 1080I through DVI looks great. Something isn't right, I suspect it's the 811's design.

 

[Stacy A]

After reading the last couple of posts I tend to agree with you sprintcarcrazy. Something must be off with the 811 and DVI ouptut. I haven't heard a single person say they get a better picture using DVI. I haven't even heard anyone say they get equal picture quality whether using DVI or Component.

 

[sprintcarcrazy]

Can't tell much Difference on the JVC, Both look good 1080I, so I use the DVI as I have only one component and use the DVD player on it.

 

[ajohnson]

My 811 sends 1080i to my LCD, a Viewsonic N3020w, just fine. I has to be something in the tv deciding to convert it to progressive scan instead of interlaced.